Recent official statistics of life expectancy after age 45 indicate that the population of Puerto Rico currently appears to be one of the most longevous in the world, with levels of survival for males and females exceeding those in the United States. Despite their disadvantaged socioeconomic status, Puerto Rican males and females exhibit substantially lower death rates from heart disease and malignant neoplasms of all sites - disease which generally account for about two-thirds of all deaths among persons aged 45 and over. It is proposed to utilize demographic techniques: 1) to determine the extent to which age reporting in the census and in the death certificate - the two records from which mortality data are derived - may be faulty, and 2) to adjust the mortality data when necessary. Pursuant to the preparation of accurate estimates of age-specific mortality risks among Puerto Ricans, the study will be directed toward a consideration of the effects of environmental and social factors on mortality patterns. Analytic study will include the examination of extant data on the presence or absence among Puerto Ricans of major risk factors associated with specific illnesses. Mortality rates for the Puerto Rican-born population in the U.S. mainland (viz. New York) will be used to provide evidence concerning host and environmental factors. Cause-specific mortality data for Puerto Rico will be compared with similar data from other Latin American areas to determine whether significant differences are detected. Morbidity statistics such as incidence data available from the population-based cancer registry in Puerto Rico will be compared with data from the cancer registry in New York. Surveys of health characteristics of Puerto Ricans, resident on the island and in the U.S. mainland will be examined and compared. The objectives of the study are to determine: a) the accuracy of current mortality rates of Puerto Ricans, b) the cultural and biological factors that may account for the Puerto Rican longevity advantage, and c) the implications of the high longevity on the future of an aging population in Puerto Rico.